Ceramic electronic component and ceramic electronic apparatus

ABSTRACT

A ceramic electronic component includes a ceramic element, a first inner electrode, a second inner electrode, an outer electrode, and a first auxiliary electrode. The first auxiliary electrode extends to a first surface of the ceramic element. The first inner electrode extends along a first direction on the first surface. The first auxiliary electrode extends outward from the region where the first inner electrode is disposed in the first direction on the first surface. The outer electrode covers the first inner electrode and the first auxiliary electrode.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a ceramic electronic component and aceramic electronic apparatus.

2. Description of the Related Art

Traditionally, components, including an integrated circuit (IC) chip anda ceramic electronic component, may be mounted on a substrate. The ICchip may be adversely affected by a flux contained in soldering. Toaddress this issue, the IC chip and the ceramic electronic component maybe electrically connected to each other by wire bonding. For example,Japanese Unexamined Utility Model Registration Application PublicationNo. 5-4451 discloses a stacked capacitor electrically connected to an ICchip by wire bonding.

In recent years, miniaturization of ceramic electronic components hasmade it difficult to precisely form outer electrodes for use inconnecting wires to the ceramic electronic components. One example of amethod of precisely forming an outer electrode is a method of formingthe outer electrode directly by plating, as disclosed in JapaneseUnexamined Patent Application Publication No. 2004-327983.

However, when an outer electrode is formed directly by plating, moisturetends to enter the inside of the ceramic electronic component frombetween the outer electrode and the ceramic element or other areas. Thiscauses a problem in that the resistance to moisture in the ceramicelectronic component is reduced.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention provide a ceramicelectronic component with a high moisture resistance.

According to a preferred embodiment of the present invention, a ceramicelectronic component includes a ceramic element, at least one firstinner electrode, a second inner electrode, an outer electrode, and afirst auxiliary electrode. The ceramic element preferably has arectangular or substantially rectangular parallelepiped shape. The atleast one first inner electrode is disposed inside the ceramic element.The first inner electrode extends to a first surface of the ceramicelement. The second inner electrode is disposed inside the ceramicelement. The second inner electrode faces the at least one first innerelectrode. The second inner electrode extends to an opposite surface ofthe ceramic element, the opposite surface being opposed to the firstsurface. The outer electrode is arranged on the first surface of theceramic element. The outer electrode is connected to the at least onefirst inner electrode. The outer electrode is defined by a plated film.The first auxiliary electrode is disposed inside the ceramic element.The first auxiliary electrode extends to the first surface of theceramic element. The at least one first inner electrode extends along afirst direction on the first surface. The first auxiliary electrodeextends outward from a region where the at least one first innerelectrode is disposed in the first direction on the first surface. Theouter electrode covers the at least one first inner electrode and thefirst auxiliary electrode.

In a specific aspect of the ceramic electronic component according to apreferred embodiment of the present invention, the at least one firstinner electrode may include a plurality of first inner electrodesextending along a second direction perpendicular or substantiallyperpendicular to the first direction, and the first auxiliary electrodemay be positioned between the plurality of first inner electrodes.

In another specific aspect of the ceramic electronic component accordingto a preferred embodiment of the present invention, the first auxiliaryelectrode may be positioned between the first inner electrode nearest toa second surface of the ceramic element and the second surface, thesecond surface being parallel or substantially parallel to the firstinner electrode.

In yet another specific aspect of the ceramic electronic componentaccording to a preferred embodiment of the present invention, the lengthof the first inner electrode in the first direction on the first surfacemay be shorter than the length of the first inner electrode in the firstdirection in a portion that is the most distant from the first surfaceinside the ceramic element.

In still another specific aspect of the ceramic electronic componentaccording to a preferred embodiment of the present invention, the firstsurface may be a principal surface.

In another specific aspect of the ceramic electronic component accordingto a preferred embodiment of the present invention, the ceramicelectronic component may further include a second auxiliary electrodedisposed inside the ceramic element and extending to the oppositesurface of the ceramic element. The first auxiliary electrode may bepositioned outside the second auxiliary electrode in the seconddirection that is perpendicular or substantially perpendicular to thefirst direction.

In yet another aspect of the ceramic electronic component according to apreferred embodiment of the present invention, the ceramic electroniccomponent may further include a third inner electrode disposed insidethe ceramic element and not extending to the surfaces of the ceramicelement.

According to another preferred embodiment of the present invention, aceramic electronic apparatus includes the above-described ceramicelectronic component, a substrate, and wire. The substrate is arrangedsuch that a principal surface of the substrate faces the oppositesurface in the ceramic electronic component. The wire is electricallyconnected to the outer electrode.

The above and other elements, features, steps, characteristics andadvantages of the present invention will become more apparent from thefollowing detailed description of the preferred embodiments withreference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic perspective view of a ceramic electronic componentaccording to a first preferred embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of the ceramic electroniccomponent according to the first preferred embodiment of the presentinvention.

FIG. 3 is a schematic plan view of the ceramic electronic componentaccording to the first preferred embodiment of the present invention.

FIG. 4 is a schematic back-side view of the ceramic electronic componentaccording to the first preferred embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view taken along the line V-V inFIG. 2.

FIG. 6 is a schematic cross-sectional view taken along the line VI-VI inFIG. 2.

FIG. 7 is a schematic cross-sectional view of a ceramic electronicapparatus according to a preferred embodiment of the present invention.

FIG. 8 is a schematic cross-sectional view of a ceramic electroniccomponent according to a second preferred embodiment of the presentinvention.

FIG. 9 is a schematic plan view of the ceramic electronic componentaccording to the second preferred embodiment of the present invention.

FIG. 10 is a schematic back-side view of the ceramic electroniccomponent according to the second preferred embodiment of the presentinvention.

FIG. 11 is a schematic cross-sectional view taken along the line XI-XIin FIG. 8.

FIG. 12 is a schematic cross-sectional view taken along the line XII-XIIin FIG. 8.

FIG. 13 is a schematic cross-sectional view of a ceramic electroniccomponent according to a third preferred embodiment of the presentinvention.

FIG. 14 is a schematic cross-sectional view of a ceramic electroniccomponent according to a fourth preferred embodiment of the presentinvention.

FIG. 15 is a schematic cross-sectional view of a ceramic electroniccomponent according to a fifth preferred embodiment of the presentinvention.

FIG. 16 is a schematic cross-sectional view of a ceramic electroniccomponent according to a sixth preferred embodiment of the presentinvention.

FIG. 17 is a schematic plan view of the ceramic electronic componentaccording to the sixth preferred embodiment of the present invention.

FIG. 18 is a schematic cross-sectional view of a ceramic electroniccomponent according to a seventh preferred embodiment of the presentinvention.

FIG. 19 is a schematic plan view of the ceramic electronic componentaccording to the seventh preferred embodiment of the present invention.

FIG. 20 is a schematic cross-sectional view of a ceramic electroniccomponent according to an eighth preferred embodiment of the presentinvention.

FIG. 21 is a schematic plan view of the ceramic electronic componentaccording to the eighth preferred embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will be further describedbelow. The preferred embodiments below are merely illustrative. Thepresent invention is not limited to the preferred embodiments describedbelow.

Members having substantially the same functions are referred to usingthe same reference numerals in the drawings referred to in thedescription of the preferred embodiments of the present invention. Thedrawings referred to in the description of the preferred embodiments ofthe present invention are schematically illustrated, and the ratios ofthe dimensions of elements in the drawings may be different from thoseof actual elements. The ratios of the dimensions of objects may bedifferent among the drawings. Specific ratios of the dimensions ofelements should be construed in consideration of the description below.

First Preferred Embodiment

FIG. 1 is a schematic perspective view of a ceramic electronic componentaccording to a first preferred embodiment of the present invention. FIG.2 is a schematic cross-sectional view of the ceramic electroniccomponent according to the first preferred embodiment. FIG. 3 is aschematic plan view of the ceramic electronic component according to thefirst preferred embodiment. FIG. 4 is a schematic back-side view of theceramic electronic component according to the first preferredembodiment. FIG. 5 is a schematic cross-sectional view taken along theline V-V in FIG. 2. FIG. 6 is a schematic cross-sectional view takenalong the line VI-VI in FIG. 2.

As illustrated in FIGS. 1 to 6, a ceramic electronic component 1includes a ceramic element 10. The ceramic element 10 preferably has theshape of a rectangular or substantially rectangular parallelepiped. Theceramic element 10 includes first and second principal surfaces 10 a and10 b facing each other, first and second side surfaces 10 c and 10 dfacing each other, and first and second end surfaces 10 e and 10 ffacing each other. Each of the first and second principal surfaces 10 aand 10 b extends along the length direction L and width direction W.Each of the first and second side surfaces 10 c and 10 d extends alongthe length direction L and thickness direction T. Each of the first andsecond end surfaces 10 e and 10 f extends along the width direction Wand thickness direction T. The length direction L and width direction Ware perpendicular or substantially perpendicular to each other. Thethickness direction T is perpendicular or substantially perpendicular toeach of the length direction L and width direction W.

The dimension in the length direction L and the dimension in the widthdirection W in the ceramic element 10 are the same or substantially thesame.

In the present invention, a “substantially rectangular parallelepiped”contains a substantially rectangular parallelepiped including a roundedcorner or ridge. That is, the ceramic element 10 may have the shape of asubstantially rectangular parallelepiped whose corners and ridges arerounded at least in part.

As illustrated in FIG. 2, the ceramic element 10 is a laminated memberin which a plurality of ceramic portions (ceramic layers) 15 are stackedalong the length direction L. The thickness of each of the ceramicportions 15 may preferably be about 0.5 μm to about 10 μm, for example.

The ceramic element 10 is made of any suitable ceramic material. Theceramic material of the ceramic element 10 is suitably selecteddepending on the characteristics of the ceramic electronic component 1.

As an example, when the ceramic electronic component 1 is a ceramiccapacitor device, the ceramic element 10 can be made of a material whosechief ingredient is a dielectric ceramic. Specific examples of thedielectric ceramic can include barium titanate (BaTiO₃), calciumtitanate (CaTiO₃), strontium titanate (SrTiO₃), and calcium zirconate(CaZrO₃). An accessory ingredient, such as a manganese compound, amagnesium compound, a silicon compound, a cobalt compound, a nickelcompound, or a rare-earth compound, may also be suitably added to theceramic element 10.

As another example, when the ceramic electronic component 1 is a ceramicpiezoelectric device, the ceramic element 10 can be made of a materialwhose chief ingredient is a piezoelectric ceramic. Specific examples ofthe piezoelectric ceramic can include a PZT-based ceramic.

As yet another example, when the ceramic electronic component 1 is athermistor device, the ceramic element 10 can be made of a semiconductorceramic. Specific examples of the semiconductor ceramic can include aspinel-based ceramic.

As still another example, when the ceramic electronic component 1 is aninductor device, the ceramic element 10 can be made of a magneticceramic. Specific examples of the magnetic ceramic can include a ferriteceramic.

In the present preferred embodiment, an example in which the ceramicelectronic component 1 is a ceramic capacitor and the ceramic element 10is made of a material whose chief ingredient is a dielectric ceramic isdescribed below.

The ceramic electronic component 1 further includes a plurality of firstinner electrodes 11 and a plurality of second inner electrodes 12disposed inside the ceramic element 10. Each of the first and secondinner electrodes 11 and 12 extends along the thickness direction T andwidth direction W inside the ceramic element 10. The plurality of firstand second inner electrodes 11 and 12 are arranged along the lengthdirection L. The first and second inner electrodes 11 and 12 arealternately arranged along the length direction L. The first and secondinner electrodes 11 and 12 face each other in the length direction Lsuch that the ceramic portion 15 is disposed therebetween. In thepresent invention, the first and second inner electrodes 11 and 12 arenot necessarily required to face each other such that the ceramicportion 15 is disposed therebetween.

The first inner electrodes 11 extend to the first principal surface 10a. The first inner electrodes 11 extend along the width direction W inthe first principal surface 10 a. The first inner electrodes 11 areexposed to none of the second principal surface 10 b, which is theopposite surface positioned on the opposite side of the first principalsurface 10 a, the first and second side surfaces 10 c and 10 d, and thefirst and second end surfaces 10 e and 10 f.

In the present preferred embodiment, as illustrated in FIG. 5, thelength X1 of each of the first inner electrodes 11 along the widthdirection W in the first principal surface 10 a is shorter than thelength X2 of the first inner electrode 11 along the width direction W inthe most distant portion from the first principal surface 10 a insidethe ceramic element 10. The present invention is not limited to thispreferred embodiment. In the present invention, the length of the firstinner electrode 11 along the width direction W in the first principalsurface 10 a may be the same as or may be longer than the length of thefirst inner electrode 11 along the width direction W inside the ceramicelement 10. From the viewpoint of increasing the area where the firstand second inner electrodes 11 and 12 face each other and ensuring thecapacity, the length of the first inner electrode 11 along the widthdirection W inside the ceramic element 10 may preferably be longer thanthe length of the first inner electrode 11 along the width direction Win the first principal surface 10 a.

The second inner electrodes 12 extend to the second principal surface 10b. The second inner electrodes 12 extend along the width direction W inthe second principal surface 10 b. The second inner electrodes 12 areexposed to none of the first principal surface 10 a, the first andsecond side surfaces 10 c and 10 d, and the first and second endsurfaces 10 e and 10 f.

In the present preferred embodiment, as illustrated in FIG. 6, thelength X3 of each of the second inner electrodes 12 along the widthdirection W in the second principal surface 10 b is shorter than thelength X4 of the second inner electrode 12 along the width direction Winside the ceramic element 10. The present invention is not limited tothis preferred embodiment. In the present invention, the length of thesecond inner electrode 12 along the width direction W in the secondprincipal surface 10 b may be the same as or may be longer than thelength of the second inner electrode 12 along the width direction Winside the ceramic element 10. From the viewpoint of increasing the areawhere the first and second inner electrodes 11 and 12 face each otherand ensuring the capacity, the length of the second inner electrode 12along the width direction W inside the ceramic element 10 may preferablybe longer than the length of the second inner electrode 12 along thewidth direction W in the second principal surface 10 b.

The thickness of each of the first and second inner electrodes 11 and 12may preferably be about 0.3 μm to about 2.0 μm, for example.

The first and second inner electrodes 11 and 12 can be any conductiveelement and are not particularly limited. Each of the first and secondinner electrodes 11 and 12 can be made of a metal, such as nickel,copper, silver, palladium, or gold, or an alloy that includes at leastone of these metals, such as a silver-palladium alloy.

The ceramic electronic component 1 further includes rectangular orsubstantially rectangular first and second auxiliary electrodes 16 and17 disposed inside the ceramic element 10. In the present invention, an“auxiliary electrode” is an electrode that does not virtually contributeto achieving the functions of the ceramic electronic component. Each ofthe first and second auxiliary electrodes 16 and 17 can be made of thesame metal or alloy as that of each of the first and second innerelectrodes.

As illustrated in FIG. 3, at least one of the plurality of firstauxiliary electrodes 16 is positioned between the plurality of firstinner electrodes 11. At least one of the plurality of first auxiliaryelectrodes 16 is positioned between the first inner electrode 11 nearestto the first end surface 10 e, which is a surface of the ceramic element10 that is parallel or substantially parallel to the first innerelectrodes 11, and the first end surface 10 e. At least one of theplurality of first auxiliary electrodes 16 is positioned between thefirst inner electrode 11 nearest to the second end surface 10 f, whichis a surface of the ceramic element 10 that is parallel or substantiallyparallel to the first inner electrodes 11, and the second end surface 10f.

The first auxiliary electrodes 16 extend to the first principal surface10 a. The first auxiliary electrodes 16 extend along the width directionW in the first principal surface 10 a. The first auxiliary electrodes 16are exposed to none of the second principal surface 10 b, the first andsecond side surfaces 10 c and 10 d, and the first and second endsurfaces 10 e and 10 f. The first auxiliary electrodes 16 extend outwardfrom the region where the first inner electrodes 11 are disposed in thewidth direction W in the first principal surface 10 a.

As illustrated in FIG. 4, at least one of the plurality of secondauxiliary electrodes 17 is positioned between the plurality of secondinner electrodes 12. At least one of the plurality of second auxiliaryelectrodes 17 is positioned between the second inner electrode 12nearest to the first end surface 10 e, which is a surface of the ceramicelement 10 that is parallel or substantially parallel to the secondinner electrodes 12, and the first end surface 10 e. At least one of theplurality of second auxiliary electrodes 17 is positioned between thesecond inner electrode 12 nearest to the second end surface 10 f, whichis a surface of the ceramic element 10 that is parallel or substantiallyparallel to the second inner electrodes 12, and the second end surface10 f.

The second auxiliary electrodes 17 are exposed to none of the firstprincipal surface 10 a, the first and second side surfaces 10 c and 10d, and the first and second end surfaces 10 e and 10 f. The secondauxiliary electrodes 17 extend outward from the region where the secondinner electrodes 12 are disposed in the width direction W in the secondprincipal surface 10 b. As illustrated in FIG. 3, the ceramic electroniccomponent 1 includes first auxiliary electrodes positioned outside thesecond auxiliary electrodes 17 in the length direction L, which isperpendicular or substantially perpendicular to the width direction W.

An outer electrode 20 is arranged on each of the first and secondprincipal surfaces 10 a and 10 b of the ceramic element 10. The outerelectrode 20 on the first principal surface 10 a is connected to thefirst inner electrodes 11. The outer electrode 20 on the secondprincipal surface 10 b is connected to the second inner electrodes 12.The outer electrode 20 on the first principal surface 10 a covers thefirst inner electrodes 11 and the first auxiliary electrodes 16. Theouter electrode 20 on the second principal surface 10 b covers thesecond inner electrodes 12 and the second auxiliary electrodes 17.

The outer electrode 20 is preferably defined by at least one platedfilm. The outer electrode 20 may include a laminate of a plurality ofplated films. The thickness of one plated film may preferably be about 1μm to about 15 μm, for example.

The outer electrode 20 can be made of a metal, such as copper, nickel,tin, extend, gold, silver, palladium, bismuth, or zinc, or an alloy thatincludes at least one of these metals, for example. The outer electrode20 may preferably include a three-layer structure of copper, nickel, andgold or a two-layer structure of nickel and gold, for example.

Next, one example of a method of manufacturing the ceramic electroniccomponent 1 will be described.

First, a ceramic green sheet including a ceramic material for formingthe ceramic element 10 is prepared. Then, a conductive pattern is formedon the ceramic green sheet by applying conductive paste.

Then, a plurality of ceramic green sheets with no conductive patterns,ceramic green sheets each including a conductive pattern of the shapecorresponding to the first or second inner electrode 11 or 12 or thefirst or second auxiliary electrode 16 or 17, a plurality of ceramicgreen sheets with no conductive patterns are stacked in this order, andthe laminate is pressed in the stacking direction, so as to produce themother laminate.

Then, the mother laminate is cut along virtual cutting lines thereon, soas to produce a plurality of green ceramic laminates from the motherlaminate.

Then, the green ceramic laminates are fired. In this firing process, thefirst and second inner electrodes 11 and 12 and the first and secondauxiliary electrodes 16 and 17 are fired.

Then, the outer electrode 20, which will be formed from a plated film,is formed on each of the fired ceramic laminates by plating. In thisway, the ceramic electronic component 1 can be manufactured.

In the ceramic electronic component 1, the first auxiliary electrodes 16extend outward from the region where the first inner electrodes 11 aredisposed in the width direction W in the first principal surface 10 a.Accordingly, if plating solution used in forming a plated film ormoisture in the atmosphere enters the surface of the outer electrodefrom between the ceramic element 10 and the outer electrode 20, the pathalong which the moisture will reach the first inner electrodes 11 can beextended. In other words, the moisture entering from between the edge ofthe outer electrode 20 and the ceramic element 10 tends to enter thefirst auxiliary electrodes 16 before reaching the first inner electrodes11. Thus a decrease in insulation resistance does not easily occur inthe first inner electrodes 11. Accordingly, the ceramic electroniccomponent 1 is highly resistant to moisture.

In connecting wire to the outer electrode in the ceramic electroniccomponent, the outer electrode may be separated from the ceramicelement, depending on the force on the outer electrode during connectingthe wire or after connecting the wire. For the ceramic electroniccomponent 1, because the area of the region where the plated filmforming the outer electrode 20 and the first auxiliary electrodes 16 areattached to each other is large, the adhesive strength of the outerelectrode 20 to the ceramic element is high. Accordingly, when the wireis connected to the outer electrode 20 on the first principal surface 10a, the outer electrode 20 is not easily separated from the ceramicelement 10.

One or more of the first auxiliary electrodes 16 are positioned betweenthe first inner electrode 11 nearest to the first end surface 10 e ofthe ceramic element 10 and the first end surface 10 e in the ceramicelectronic component 1. Thus, the adhesive strength between the outerelectrode 20 and the ceramic element 10 at the end portion of the outerelectrode 20 is higher. Another one or more of the first auxiliaryelectrodes 16 are positioned between the first inner electrode 11nearest to the second end surface 10 f of the ceramic element 10 and thesecond end surface 10 f. Thus, the adhesive strength between the outerelectrode 20 and the ceramic element 10 at the end portion of the outerelectrode 20 is higher.

The area of the first auxiliary electrodes 16 is larger than that of thefirst inner electrodes 11 in the first principal surface 10 a in theceramic electronic component 1. Thus, the adhesive strength between theouter electrode 20 and the ceramic element 10 is further increased.

The first principal surface 10 a, to which the first auxiliaryelectrodes 16 are exposed, is a principal surface whose area is largerthan each of the first and second side surfaces 10 c and 10 d and thefirst and second end surfaces 10 e and 10 f. Thus, the area of the outerelectrode 20 is large. In such a case, the advantageous effect achievedby an increase in adhesive strength between the ceramic element 10 andthe outer electrode 20 is great.

The ceramic electronic component 1 can be used as a component in aceramic electronic apparatus 1 a illustrated in FIG. 7, for example. Theceramic electronic apparatus 1 a includes the ceramic electroniccomponent 1, a substrate 50, and wire 80. The ceramic electroniccomponent 1 is arranged such that the second principal surface 10 bfaces a principal surface 50 a of the substrate 50. The substrate 50 isprovided with a land 60. The ceramic electronic component 1 is arrangedsuch that the outer electrode 20 on the second principal surface 10 bfaces the land 60 with a curing agent 70 of conductive adhesive beingdisposed therebetween.

The wire 80 is electrically connected to the outer electrode 20 on thefirst principal surface 10 a such that the curing agent 70 of conductiveadhesive is disposed therebetween.

The ratio of the area of the first auxiliary electrodes 16 in the firstprincipal surface 10 a to that of the first inner electrodes 11 islarger than the ratio of the area of the second auxiliary electrodes 17in the second principal surface 10 b to that of the second innerelectrodes 12 in the ceramic electronic component 1. Thus, for example,the area of the outer electrode 20 on the first principal surface 10 acan be large, and the area of the outer electrode 20 on the secondprincipal surface 10 b can be small. If the area of the outer electrode20 on the first principal surface 10 a is large, it is easy to connectwire to the outer electrode 20 on the first principal surface 10 a. Ifthe area of the outer electrode 20 on the second principal surface 10 bis small, a problem, such as a short circuit caused by the outerelectrode 20 coming into contact with another electronic component, doesnot easily occur in arranging the outer electrode 20 directly above theland 60 on the substrate 50, as illustrated in FIG. 7.

Other examples of preferred embodiments of the present invention aredescribed below. In the following description, members havingsubstantially common functions as in the above first preferredembodiment are referred to using common reference numerals, and thedescription thereof is omitted.

Second Preferred Embodiment

FIG. 8 is a schematic cross-sectional view of a ceramic electroniccomponent according to a second preferred embodiment of the presentinvention. FIG. 9 is a schematic plan view of the ceramic electroniccomponent according to the second preferred embodiment. FIG. 10 is aschematic back-side view of the ceramic electronic component accordingto the second preferred embodiment. FIG. 11 is a schematiccross-sectional view taken along the line XI-XI in FIG. 8. FIG. 12 is aschematic cross-sectional view taken along the line XII-XII in FIG. 8.

As illustrated in FIGS. 8 to 12, in a ceramic electronic component 2,the first inner electrodes 11 and the second inner electrodes 12 arealigned in the thickness direction T. The first auxiliary electrodes 16and the second auxiliary electrodes 17 are aligned in the thicknessdirection T.

The ceramic electronic component 2 includes third inner electrodes 13.The third inner electrodes 13 do not extend to the surfaces of theceramic element 10. The third inner electrodes 13 are positioned betweenthe plurality of first inner electrodes 11 and the plurality of secondinner electrodes 12 and face each of the first inner electrodes 11 andthe second inner electrodes 12 in the thickness direction T. The thirdinner electrodes 13 and the first and second auxiliary electrodes 16 and17 are aligned in the thickness direction T. The ceramic electroniccomponent 2 can also provide substantially the same advantageous effectsas in the ceramic electronic component 1.

Third Preferred Embodiment

FIG. 13 is a schematic cross-sectional view of a ceramic electroniccomponent according to a third preferred embodiment of the presentinvention. As illustrated in FIG. 13, a ceramic electronic component 3according to the third preferred embodiment includes the third innerelectrodes 13, as in the ceramic electronic component 2 according to thesecond preferred embodiment. One or more of the first auxiliaryelectrodes 16 are positioned between the first inner electrode 11nearest to the first end surface 10 e of the ceramic element 10 and thefirst end surface 10 e in the ceramic electronic component 3. Anotherone or more of the first auxiliary electrodes 16 are positioned betweenthe first inner electrode 11 nearest to the second end surface 10 f ofthe ceramic element 10 and the second end surface 10 f. Thus, theadhesive strength between the outer electrode 20 and the ceramic element10 is higher.

Fourth Preferred Embodiment

FIG. 14 is a schematic cross-sectional view of a ceramic electroniccomponent according to a fourth preferred embodiment of the presentinvention. As illustrated in illustrated in FIG. 14, a ceramicelectronic component 4 according to the fourth preferred embodimentincludes the third inner electrodes 13, as in the ceramic electroniccomponent 2 according to the second preferred embodiment. One or more ofthe first auxiliary electrodes 16 are positioned between the first innerelectrode 11 nearest to the first end surface 10 e of the ceramicelement 10 and the first end surface 10 e in the ceramic electroniccomponent 4, as in the ceramic electronic component 3 according to thethird preferred embodiment. Another one or more of the first auxiliaryelectrodes 16 are positioned between the first inner electrode 11nearest to the second end surface 10 f of the ceramic element 10 and thesecond end surface 10 f. In the ceramic electronic component 4, one ormore of the third inner electrodes 13 are also positioned between thefirst inner electrode 11 nearest to the first end surface 10 e of theceramic element 10 and the first end surface 10 e. Another one or moreof the third inner electrodes 13 are also positioned between the firstinner electrode 11 nearest to the second end surface 10 f of the ceramicelement 10 and the second end surface 10 f. The ceramic electroniccomponent 4 may be preferable in terms of its manufacturing cost becausethe arrangement of the inner electrodes can be made up of two kinds ofpatterns.

Fifth Preferred Embodiment

FIG. 15 is a schematic cross-sectional view of a ceramic electroniccomponent according to a fifth preferred embodiment of the presentinvention. As illustrated in FIG. 15, a ceramic electronic component 5according to the fifth preferred embodiment includes the third innerelectrodes 13, as in the ceramic electronic component 2 according to thesecond preferred embodiment. In the ceramic electronic component 5, theplurality of first auxiliary electrodes 16 are arranged between thefirst inner electrodes 11. Thus the probability that moisture frombetween the outer electrode 20 and the ceramic element 10 will reach anauxiliary electrode is higher than the probability that the moisturewill reach an inner electrode. Accordingly, the ceramic electroniccomponent 5 has a high resistance to moisture.

Sixth Preferred Embodiment

FIGS. 16 and 17 are a schematic cross-sectional view and a schematicplan view, respectively, of a ceramic electronic component according toa sixth preferred embodiment of the present invention.

The first inner electrodes 11 and second inner electrodes 12 in theceramic electronic component 6 according to the sixth preferredembodiment are arranged in the ceramic element 10 in substantially thesame manner as in the first preferred embodiment. In the presentpreferred embodiment, each of the first inner electrodes 11 and secondinner electrodes 12 is a split inner electrode. That is, the first innerelectrode includes two electrode layers 11 a and 11 b connected to thesame potential. The electrode layers 11 a and 11 b overlap each othersuch that a ceramic layer is disposed therebetween. The second innerelectrode 12 includes two electrode layers 12 a and 12 b, as in thefirst inner electrode 11. As in this case, each of the first and secondinner electrodes may be a split inner electrode.

The first and second auxiliary electrodes 16 and 17 are also disposed inthe sixth preferred embodiment, as in the first preferred embodiment.Each of the first auxiliary electrodes 16 is a split electrode includingtwo electrode layers 16 a and 16 b, and each of the second auxiliaryelectrodes 17 is a split electrode including two electrode layers 17 aand 17 b.

The description is provided below using the first auxiliary electrodes16 with reference to FIG. 17. The first auxiliary electrodes 16 extendoutward from the region where the first inner electrodes 11 are disposedin the width direction W. Accordingly, the resistance to moisture can beenhanced, as in the first preferred embodiment.

In the present preferred embodiment, as illustrated in FIG. 17, thirdauxiliary electrodes 21 are disposed in the ceramic element 10. Thethird auxiliary electrodes 21 are exposed to the region where the firstinner electrodes 11 are disposed in the width direction W and do notreach the portion outside that region in the width direction W. As inthis case, an auxiliary electrode such as the third auxiliary electrode21 may be further included as another auxiliary electrode that does notreach the region where the inner electrodes are disposed in the presentinvention. The other respects of the sixth preferred embodiment aresubstantially the same as in the first preferred embodiment.

Seventh Preferred Embodiment

FIGS. 18 and 19 are a schematic cross-sectional view and a schematicplan view of a ceramic electronic component 7 according to a seventhpreferred embodiment, respectively. The ceramic electronic component 7according to the present preferred embodiment is substantially the sameas the sixth preferred embodiment, except for where the first and secondauxiliary electrodes 16 and 17 are formed. The difference is that thefirst auxiliary electrodes 16 are positioned over the end portion of theregion where the first inner electrodes 11 are disposed in the firstprincipal surface 10 a in the width direction W, as illustrated in FIG.19. In other words, the first auxiliary electrodes 16 do not reach thecentral region of each of the first and second inner electrodes 11 and12 in the width direction W.

Although not explicitly illustrated in FIG. 19, the second auxiliaryelectrodes 17 illustrated in FIG. 18 also do not reach the centralregion in the width direction W in the second principal surface 10 b, towhich the second inner electrodes 12 are exposed. As in this case, thefirst and second auxiliary electrodes 16 and 17 may be arranged only inthe vicinity of the end portion where the first and second innerelectrodes 11 and 12 are disposed so as to be positioned over that endportion in the present invention.

Eighth Preferred Embodiment

FIGS. 20 and 21 are a schematic cross-sectional view and a schematicplan view, respectively, of a ceramic electronic component according toan eighth preferred embodiment of the present invention.

A ceramic electronic component 8 according to the eighth preferredembodiment is substantially the same as the sixth preferred embodiment,except for the first and second auxiliary electrodes 16 and 17. In thepresent preferred embodiment, as illustrated in FIG. 21, the firstauxiliary electrodes 16 reach both ends in the width direction W in thefirst principal surface 10 a. That is, the first auxiliary electrodes 16reach both ends in the width direction W inside the ceramic element 10,in other words, both the first and second side surfaces 10 c and 10 d.The second auxiliary electrodes 17 are disposed in substantially thesame manner.

Accordingly, the first and second auxiliary electrodes 16 and 17 areexposed to the first and second side surfaces 10 c and 10 d. Thus, it isdesirable that the outer electrode 20 be formed so as to include afolded portion that reaches the first and second side surfaces 10 c and10 d. Because the first and second auxiliary electrodes 16 and 17 areexposed to the first and second side surfaces 10 c and 10 d, the foldedportion can be formed reliably. This can enable the path along whichplating solution or moisture from the outside will reach the first andsecond inner electrodes 11 and 12 to be longer than that in each of thefirst preferred embodiment and sixth preferred embodiment. Accordingly,the resistance to moisture can be further enhanced, as described above.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing from the scopeand spirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

What is claimed is:
 1. A ceramic electronic component comprising: aceramic element; at least one first inner electrode disposed inside theceramic element and extending to a first surface of the ceramic element;a second inner electrode disposed inside the ceramic element, facing theat least one first inner electrode, and extending to an opposite surfaceof the ceramic element, the opposite surface being opposed to the firstsurface; an outer electrode arranged on the first surface of the ceramicelement, connected to the at least one first inner electrode, andincluding a plated film; and a first auxiliary electrode disposed insidethe ceramic element and extending to the first surface of the ceramicelement; wherein the at least one first inner electrode extends along afirst direction on the first surface; the first auxiliary electrodeextends outward from a region where the at least one first innerelectrode is disposed in the first direction on the first surface; andthe outer electrode covers the at least one first inner electrode andthe first auxiliary electrode.
 2. The ceramic electronic componentaccording to claim 1, wherein the at least one first inner electrodeincludes a plurality of first inner electrodes extending along a seconddirection perpendicular or substantially perpendicular to the firstdirection; and the first auxiliary electrode is positioned between theplurality of first inner electrodes.
 3. The ceramic electronic componentaccording to claim 1, wherein the first auxiliary electrode ispositioned between the first inner electrode nearest to a second surfaceof the ceramic element and the second surface, the second surface beingparallel or substantially parallel to the first inner electrode.
 4. Theceramic electronic component according to claim 1, wherein a length ofthe first inner electrode in the first direction on the first surface isshorter than a length of the first inner electrode in the firstdirection in a portion that is most distant from the first surfaceinside the ceramic element.
 5. The ceramic electronic componentaccording to claim 1, wherein the first surface includes a principalsurface of the ceramic element.
 6. The ceramic electronic componentaccording to claim 1, further comprising a second auxiliary electrodedisposed inside the ceramic element and extending to the oppositesurface of the ceramic element; wherein the first auxiliary electrode ispositioned outside the second auxiliary electrode in the seconddirection that is parallel or substantially perpendicular to the firstdirection.
 7. The ceramic electronic component according to claim 1,further comprising a third inner electrode disposed inside the ceramicelement and not extending to the surfaces of the ceramic element.
 8. Theceramic electronic component according to claim 1, wherein the ceramicelement has a rectangular or substantially rectangular parallelepipedshape.
 9. The ceramic electronic component according to claim 1, whereinthe ceramic element includes a plurality of ceramic layers stacked oneach other.
 10. The ceramic electronic component according to claim 1,wherein the ceramic electronic component is one of a capacitor, apiezoelectric device, a thermistor, and an inductor.
 11. The ceramicelectronic component according to claim 1, wherein the at least onefirst inner electrode is not exposed at any of a second surface, firstand second side surfaces, and first and second end surfaces of theceramic element.
 12. The ceramic electronic component according to claim1, wherein the second inner electrode is not exposed at any of a secondsurface, first and second side surfaces, and first and second endsurfaces of the ceramic element.
 13. The ceramic electronic componentaccording to claim 1, wherein the at least one first inner electrode andthe second inner electrode are aligned in a thickness direction of theceramic element.
 14. The ceramic electronic component according to claim7, wherein the third inner electrode is disposed between the at leastone first inner electrode and the second inner electrode.
 15. Theceramic electronic component according to claim 6, wherein the firstauxiliary electrode is positioned between the at least one first innerelectrode and an end surface of the ceramic element.
 16. A ceramicelectronic apparatus comprising: the ceramic electronic componentaccording to claim 1; a substrate arranged such that a principal surfaceof the substrate faces the opposite surface in the ceramic electroniccomponent; and at least one wire electrically connected to the outerelectrode.